Re: [PATCH] Add support for power_supply on tosa

Anton Vorontsov
2008-06-23T06:20:13Z

On Fri, Jun 20, 2008 at 12:49:17PM +0400, Dmitry Baryshkov wrote:
> Support the battery management on Sharp Zaurus SL-6000.
>
> This patch depends on the tc6393xb support as found in the arm:devel
> or linux-next trees.
>
> Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
> ---

On Sun, Jun 22, 2008 at 07:21:09PM +0400, Dmitry Baryshkov wrote:
> Any comments on this? As this driver is protected by necessary
> dependencies in Kconfig, it can be merged even now.

Thanks for the patch and sorry for the delayed review. Few comments
below.

> drivers/power/Kconfig | 7 +
> drivers/power/Makefile | 1 +
> drivers/power/tosa_battery.c | 485 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 493 insertions(+), 0 deletions(-)
> create mode 100644 drivers/power/tosa_battery.c
>
> diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
> index 58c806e..e3a9c37 100644
> --- a/drivers/power/Kconfig
> +++ b/drivers/power/Kconfig
> @@ -49,4 +49,11 @@ config BATTERY_OLPC
> help
> Say Y to enable support for the battery on the OLPC laptop.
>
> +config BATTERY_TOSA
> + tristate "Sharp SL-6000 (tosa) battery"
> + depends on MACH_TOSA && MFD_TC6393XB
> + help
> + Say Y to enable support for the battery on the Sharp Zaurus
> + SL-6000 (tosa) models.
> +
> endif # POWER_SUPPLY
> diff --git a/drivers/power/Makefile b/drivers/power/Makefile
> index 6413ded..1e408fa 100644
> --- a/drivers/power/Makefile
> +++ b/drivers/power/Makefile
> @@ -20,3 +20,4 @@ obj-$(CONFIG_APM_POWER) += apm_power.o
> obj-$(CONFIG_BATTERY_DS2760) += ds2760_battery.o
> obj-$(CONFIG_BATTERY_PMU) += pmu_battery.o
> obj-$(CONFIG_BATTERY_OLPC) += olpc_battery.o
> +obj-$(CONFIG_BATTERY_TOSA) += tosa_battery.o
> diff --git a/drivers/power/tosa_battery.c b/drivers/power/tosa_battery.c
> new file mode 100644
> index 0000000..7a99203
> --- /dev/null
> +++ b/drivers/power/tosa_battery.c
> @@ -0,0 +1,485 @@
> +/*
> + * Battery and Power Management code for the Sharp SL-6000x
> + *
> + * Copyright (c) 2005 Dirk Opfer
> + * Copyright (c) 2008 Dmitry Baryshkov
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/power_supply.h>
> +#include <linux/wm97xx.h>
> +#include <linux/delay.h>
> +#include <linux/spinlock.h>
> +#include <linux/interrupt.h>
> +#include <linux/gpio.h>
> +
> +#include <asm/mach-types.h>
> +#include <asm/arch/tosa.h>
> +
> +static DEFINE_MUTEX(bat_lock); /* protects gpio pins */
> +static struct work_struct bat_work;
> +
> +struct tosa_bat {
> + int status;
> + struct power_supply psy;
> + int full_chrg;
> +
> + struct mutex work_lock; /* protects data */
> +
> + bool (*is_present)(struct tosa_bat *bat);
> + int gpio_full;
> + int gpio_charge_off;
> +
> + int technology;
> +
> + int gpio_bat;
> + int adc_bat;
> + int adc_bat_divider;
> + int bat_max;
> + int bat_min;
> +
> + int gpio_temp;
> + int adc_temp;
> + int adc_temp_divider;
> +};
> +
> +static struct tosa_bat tosa_bat_main;
> +static struct tosa_bat tosa_bat_jacket;
> +
> +static unsigned long tosa_read_bat(struct tosa_bat *bat)
> +{
> + unsigned long value = 0;
> +
> + if (bat->gpio_bat < 0 || bat->adc_bat < 0)
> + return 0;
> +
> + mutex_lock(&bat_lock);
> + gpio_set_value(bat->gpio_bat, 1);
> + mdelay(5);

msleep() can be used here.

> + value = wm97xx_read_aux_adc(bat->psy.dev->parent->driver_data,
> + bat->adc_bat);
> + gpio_set_value(bat->gpio_bat, 0);
> + mutex_unlock(&bat_lock);
> +
> + value = value * 1000000 / bat->adc_bat_divider;
> +
> + return value;
> +}
> +
> +static unsigned long tosa_read_temp(struct tosa_bat *bat)
> +{
> + unsigned long value = 0;
> +
> + if (bat->gpio_temp < 0 || bat->adc_temp < 0)
> + return 0;
> +
> + mutex_lock(&bat_lock);
> + gpio_set_value(bat->gpio_temp, 1);
> + mdelay(5);

Ditto.

> + value = wm97xx_read_aux_adc(bat->psy.dev->parent->driver_data,
> + bat->adc_temp);
> + gpio_set_value(bat->gpio_temp, 0);
> + mutex_unlock(&bat_lock);
> +
> + value = value * 10000 / bat->adc_temp_divider;
> +
> + return value;
> +}
> +
> +static int tosa_bat_get_property(struct power_supply *psy,
> + enum power_supply_property psp,
> + union power_supply_propval *val)
> +{
> + int ret = 0;
> + struct tosa_bat *bat = container_of(psy, struct tosa_bat, psy);
> +
> + if (bat->is_present && !bat->is_present(bat)
> + && psp != POWER_SUPPLY_PROP_PRESENT) {
> + return -ENODEV;
> + }
> +
> + switch (psp) {
> + case POWER_SUPPLY_PROP_STATUS:
> + val->intval = bat->status;
> + break;
> + case POWER_SUPPLY_PROP_TECHNOLOGY:
> + val->intval = bat->technology;
> + break;
> + case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> + val->intval = tosa_read_bat(bat);
> + break;
> + case POWER_SUPPLY_PROP_VOLTAGE_MAX:
> + if (bat->full_chrg == -1)
> + val->intval = bat->bat_max;
> + else
> + val->intval = bat->full_chrg;
> + break;
> + case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
> + val->intval = bat->bat_max;
> + break;
> + case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
> + val->intval = bat->bat_min;
> + break;
> + case POWER_SUPPLY_PROP_TEMP:
> + val->intval = tosa_read_temp(bat);
> + break;
> + case POWER_SUPPLY_PROP_PRESENT:
> + val->intval = bat->is_present ? bat->is_present(bat) : 1;
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> + return ret;
> +}
> +
> +static bool tosa_jacket_bat_is_present(struct tosa_bat *bat)
> +{
> + return gpio_get_value(TOSA_GPIO_JACKET_DETECT) == 0;
> +}
> +
> +static void tosa_bat_external_power_changed(struct power_supply *psy)
> +{
> + schedule_work(&bat_work);
> +}
> +
> +static irqreturn_t tosa_bat_gpio_isr(int irq, void *data)
> +{
> + printk(KERN_ERR "bat_gpio irq: %d\n", gpio_get_value(irq_to_gpio(irq)));

Are you sure that this needs KERN_ERR?

> + schedule_work(&bat_work);
> + return IRQ_HANDLED;
> +}
> +
> +static char *status_text[] = {
> + [POWER_SUPPLY_STATUS_UNKNOWN] = "Unknown",
> + [POWER_SUPPLY_STATUS_CHARGING] = "Charging",
> + [POWER_SUPPLY_STATUS_DISCHARGING] = "Discharging",
> + [POWER_SUPPLY_STATUS_NOT_CHARGING] = "Not charging",
> + [POWER_SUPPLY_STATUS_FULL] = "Full",
> +};
> +
> +static void tosa_bat_update(struct tosa_bat *bat)
> +{
> + int old;
> + struct power_supply *psy = &bat->psy;
> +
> + mutex_lock(&bat->work_lock);
> +
> + old = bat->status;
> +
> + if (bat->is_present && !bat->is_present(bat)) {
> + printk(KERN_NOTICE "%s not present\n", psy->name);
> + bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;

NOT_CHARGING is an error (usually), e.g. not charging because battery is
broken. In case of absent battery, status should be STATUS_UNKNOWN.

(..I should document that.)

> + bat->full_chrg = -1;
> + } else if (power_supply_am_i_supplied(psy)) {
> + if (bat->status == POWER_SUPPLY_STATUS_DISCHARGING) {
> + gpio_set_value(bat->gpio_charge_off, 0);
> + mdelay(15);
> + }
> +
> + if (gpio_get_value(bat->gpio_full)) {
> + if (old == POWER_SUPPLY_STATUS_CHARGING ||
> + bat->full_chrg == -1)
> + bat->full_chrg = tosa_read_bat(bat);
> +
> + gpio_set_value(bat->gpio_charge_off, 1);
> + bat->status = POWER_SUPPLY_STATUS_FULL;
> + } else {
> + gpio_set_value(bat->gpio_charge_off, 0);
> + bat->status = POWER_SUPPLY_STATUS_CHARGING;
> + }
> + } else {
> + gpio_set_value(bat->gpio_charge_off, 1);
> + bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
> + }
> +
> + if (old != bat->status) {
> + printk(KERN_NOTICE "%s %s -> %s\n", psy->name,
> + status_text[old],
> + status_text[bat->status]);

Not sure if printing the notice for every status change is a good
idea...

If removed, we could also remove static char *status_text[]. :-)

> + power_supply_changed(psy);
> + }
> +
> + mutex_unlock(&bat->work_lock);
> +}
> +
> +static void tosa_bat_work(struct work_struct *work)
> +{
> + tosa_bat_update(&tosa_bat_main);
> + tosa_bat_update(&tosa_bat_jacket);
> +}
> +
> +
> +static enum power_supply_property tosa_bat_main_props[] = {
> + POWER_SUPPLY_PROP_STATUS,
> + POWER_SUPPLY_PROP_TECHNOLOGY,
> + POWER_SUPPLY_PROP_VOLTAGE_NOW,
> + POWER_SUPPLY_PROP_VOLTAGE_MAX,
> + POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
> + POWER_SUPPLY_PROP_TEMP,
> + POWER_SUPPLY_PROP_PRESENT,
> +};
> +
> +static enum power_supply_property tosa_bat_bu_props[] = {
> + POWER_SUPPLY_PROP_STATUS,
> + POWER_SUPPLY_PROP_TECHNOLOGY,
> + POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
> + POWER_SUPPLY_PROP_VOLTAGE_NOW,
> + POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
> + POWER_SUPPLY_PROP_PRESENT,
> +};
> +
> +static struct tosa_bat tosa_bat_main = {
> + .status = POWER_SUPPLY_STATUS_DISCHARGING,
> + .full_chrg = -1,
> + .psy = {
> + .name = "main-battery",
> + .type = POWER_SUPPLY_TYPE_BATTERY,
> + .properties = tosa_bat_main_props,
> + .num_properties = ARRAY_SIZE(tosa_bat_main_props),
> + .get_property = tosa_bat_get_property,
> + .external_power_changed = tosa_bat_external_power_changed,
> + .use_for_apm = 1,
> + },
> +
> + .gpio_full = TOSA_GPIO_BAT0_CRG,
> + .gpio_charge_off = TOSA_GPIO_CHARGE_OFF,
> +
> + .technology = POWER_SUPPLY_TECHNOLOGY_LIPO,
> +
> + .gpio_bat = TOSA_GPIO_BAT0_V_ON,
> + .adc_bat = WM97XX_AUX_ID3,
> + .adc_bat_divider = 414,
> + .bat_max = 4310000,
> + .bat_min = 1551 * 1000000 / 414,
> +
> + .gpio_temp = TOSA_GPIO_BAT1_TH_ON,
> + .adc_temp = WM97XX_AUX_ID2,
> + .adc_temp_divider = 10000,
> +};
> +
> +static struct tosa_bat tosa_bat_jacket = {
> + .status = POWER_SUPPLY_STATUS_DISCHARGING,
> + .full_chrg = -1,
> + .psy = {
> + .name = "jacket-battery",
> + .type = POWER_SUPPLY_TYPE_BATTERY,
> + .properties = tosa_bat_main_props,
> + .num_properties = ARRAY_SIZE(tosa_bat_main_props),
> + .get_property = tosa_bat_get_property,
> + .external_power_changed = tosa_bat_external_power_changed,
> + },
> +
> + .is_present = tosa_jacket_bat_is_present,
> + .gpio_full = TOSA_GPIO_BAT1_CRG,
> + .gpio_charge_off = TOSA_GPIO_CHARGE_OFF_JC,
> +
> + .technology = POWER_SUPPLY_TECHNOLOGY_LIPO,
> +
> + .gpio_bat = TOSA_GPIO_BAT1_V_ON,
> + .adc_bat = WM97XX_AUX_ID3,
> + .adc_bat_divider = 414,
> + .bat_max = 4310000,
> + .bat_min = 1551 * 1000000 / 414,
> +
> + .gpio_temp = TOSA_GPIO_BAT0_TH_ON,
> + .adc_temp = WM97XX_AUX_ID2,
> + .adc_temp_divider = 10000,
> +};
> +
> +static struct tosa_bat tosa_bat_bu = {
> + .status = POWER_SUPPLY_STATUS_UNKNOWN,
> + .full_chrg = -1,
> +
> + .psy = {
> + .name = "backup-battery",
> + .type = POWER_SUPPLY_TYPE_BATTERY,
> + .properties = tosa_bat_bu_props,
> + .num_properties = ARRAY_SIZE(tosa_bat_bu_props),
> + .get_property = tosa_bat_get_property,
> + .external_power_changed = tosa_bat_external_power_changed,
> + },
> +
> + .gpio_full = -1,
> + .gpio_charge_off = -1,
> +
> + .technology = POWER_SUPPLY_TECHNOLOGY_LiMn,
> +
> + .gpio_bat = TOSA_GPIO_BU_CHRG_ON,
> + .adc_bat = WM97XX_AUX_ID4,
> + .adc_bat_divider = 1266,
> +
> + .gpio_temp = -1,
> + .adc_temp = -1,
> + .adc_temp_divider = -1,
> +};
> +
> +static struct {
> + int gpio;
> + char *name;
> + bool output;
> + int value;
> +} gpios[] = {
> + { TOSA_GPIO_CHARGE_OFF, "main charge off", 1, 1 },
> + { TOSA_GPIO_CHARGE_OFF_JC, "jacket charge off", 1, 1 },
> + { TOSA_GPIO_BAT_SW_ON, "battery switch", 1, 0 },
> + { TOSA_GPIO_BAT0_V_ON, "main battery", 1, 0 },
> + { TOSA_GPIO_BAT1_V_ON, "jacket battery", 1, 0 },
> + { TOSA_GPIO_BAT1_TH_ON, "main battery temp", 1, 0 },
> + { TOSA_GPIO_BAT0_TH_ON, "jacket battery temp", 1, 0 },
> + { TOSA_GPIO_BU_CHRG_ON, "backup battery", 1, 0 },
> + { TOSA_GPIO_BAT0_CRG, "main battery full", 0, 0 },
> + { TOSA_GPIO_BAT1_CRG, "jacket battery full", 0, 0 },
> + { TOSA_GPIO_BAT0_LOW, "main battery low", 0, 0 },
> + { TOSA_GPIO_BAT1_LOW, "jacket battery low", 0, 0 },
> + { TOSA_GPIO_JACKET_DETECT, "jacket detect", 0, 0 },
> +};
> +
> +#ifdef CONFIG_PM
> +static int tosa_bat_suspend(struct platform_device *dev, pm_message_t state)
> +{
> + /* do nothing */
> + flush_scheduled_work();

The comment is contradictory. It would be better if it explained why we
want to flush scheduled work on suspend.

> + return 0;
> +}
> +
> +static int tosa_bat_resume(struct platform_device *dev)
> +{
> + schedule_work(&bat_work);
> + return 0;
> +}
> +#else
> +#define tosa_bat_suspend NULL
> +#define tosa_bat_resume NULL
> +#endif
> +
> +static int __devinit tosa_bat_probe(struct platform_device *dev)
> +{
> + int ret;
> + int i;
> +
> + if (!machine_is_tosa())
> + return -ENODEV;
> +
> + for (i = 0; i < ARRAY_SIZE(gpios); i++) {
> + ret = gpio_request(gpios[i].gpio, gpios[i].name);
> + if (ret) {
> + i--;
> + goto err_gpio;
> + }
> +
> + if (gpios[i].output)
> + ret = gpio_direction_output(gpios[i].gpio,
> + gpios[i].value);
> + else
> + ret = gpio_direction_input(gpios[i].gpio);
> +
> + if (ret)
> + goto err_gpio;
> + }
> +
> + mutex_init(&tosa_bat_main.work_lock);
> + mutex_init(&tosa_bat_jacket.work_lock);
> +
> + INIT_WORK(&bat_work, tosa_bat_work);
> +
> + ret = power_supply_register(&dev->dev, &tosa_bat_main.psy);
> + if (ret)
> + goto err_psy_reg_main;
> + ret = power_supply_register(&dev->dev, &tosa_bat_jacket.psy);
> + if (ret)
> + goto err_psy_reg_jacket;
> + ret = power_supply_register(&dev->dev, &tosa_bat_bu.psy);
> + if (ret)
> + goto err_psy_reg_bu;
> +
> + ret = request_irq(gpio_to_irq(TOSA_GPIO_BAT0_CRG),
> + tosa_bat_gpio_isr,
> + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> + "main full", &tosa_bat_main);
> + if (ret)
> + goto err_req_main;
> +
> + ret = request_irq(gpio_to_irq(TOSA_GPIO_BAT1_CRG),
> + tosa_bat_gpio_isr,
> + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> + "jacket full", &tosa_bat_jacket);
> + if (ret)
> + goto err_req_jacket;
> +
> + ret = request_irq(gpio_to_irq(TOSA_GPIO_JACKET_DETECT),
> + tosa_bat_gpio_isr,
> + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> + "jacket detect", &tosa_bat_jacket);
> + if (!ret) {
> + schedule_work(&bat_work);
> + return 0;
> + }
> +
> + free_irq(gpio_to_irq(TOSA_GPIO_BAT1_CRG), &tosa_bat_jacket);
> +err_req_jacket:
> + free_irq(gpio_to_irq(TOSA_GPIO_BAT0_CRG), &tosa_bat_main);
> +err_req_main:
> + power_supply_unregister(&tosa_bat_bu.psy);
> +err_psy_reg_bu:
> + power_supply_unregister(&tosa_bat_jacket.psy);
> +err_psy_reg_jacket:
> + power_supply_unregister(&tosa_bat_main.psy);
> +err_psy_reg_main:
> +
> + i--;
> +err_gpio:
> + for (; i >= 0; i--)
> + gpio_free(gpios[i].gpio);
> +
> + return ret;
> +}
> +
> +static int __devexit tosa_bat_remove(struct platform_device *dev)
> +{
> + int i;
> +
> + free_irq(gpio_to_irq(TOSA_GPIO_JACKET_DETECT), &tosa_bat_jacket);
> + free_irq(gpio_to_irq(TOSA_GPIO_BAT1_CRG), &tosa_bat_jacket);
> + free_irq(gpio_to_irq(TOSA_GPIO_BAT0_CRG), &tosa_bat_main);
> +
> + power_supply_unregister(&tosa_bat_bu.psy);
> + power_supply_unregister(&tosa_bat_jacket.psy);
> + power_supply_unregister(&tosa_bat_main.psy);

Because scheduled work doing tosa_bat_update() for both
tosa_bat_main and tosa_bat_jacket, such unregistering is racy. :-/

flush_scheduled_work() will not work because external_power_changed
callback might reschedule the work again.

This isn't trivial to fix, so if you don't want to fix this for now,
I think just TODO: or FIXME: ... comment will work.

> + for (i = ARRAY_SIZE(gpios) - 1; i >= 0; i--)
> + gpio_free(gpios[i].gpio);
> +
> + return 0;
> +}
> +
> +static struct platform_driver tosa_bat_driver = {
> + .driver.name = "wm97xx-battery",
> + .driver.owner = THIS_MODULE,
> + .probe = tosa_bat_probe,
> + .remove = __devexit_p(tosa_bat_remove),
> + .suspend = tosa_bat_suspend,
> + .resume = tosa_bat_resume,
> +};
> +
> +static int __init tosa_bat_init(void)
> +{
> + return platform_driver_register(&tosa_bat_driver);
> +}
> +
> +static void __exit tosa_bat_exit(void)
> +{
> + platform_driver_unregister(&tosa_bat_driver);
> +}
> +
> +module_init(tosa_bat_init);
> +module_exit(tosa_bat_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Dmitry Baryshkov");
> +MODULE_DESCRIPTION("Tosa battery driver");
> --
> 1.5.5.3

--
Anton Vorontsov
email: cbouatmailru@gmail.com
irc://irc.freenode.net/bd2